1. Field of the Invention
The invention relates to water dispensing devices, and more particularly to lawn watering or sprinkling devices of the impulse type.
2. Description of the Prior Art
It has long been a problem in the use of lawn sprinklers to provide a pattern which will place the water only where it is needed.
Rotating sprinklers operate either under the force of an impulse device or the head rotates under the reaction of the exhaust of the water being dispensed. Because rotating sprinkler apparatus produce circular patterns and since most property boundaries are not circular, there are usually situations where it is necessary to spray large quantities of water onto areas where water is not desired, such as walkways and streets, in order to cover the desired areas with water. One alternative is to spray less than all of the desired area and to use soaking strips or hand water the areas missed by the sprinkler device. Another alternative is to move the sprinkler device to different locations within the area to be water until the entire area is watered. This procedure requires readjustment of the water pressure supplied to the sprinkler device for each location and causes overlapping areas already sprayed which results in uneven water distribution over the entire area to be watered. In in-the-ground sprinkler installations, the requirement of limiting the sprinkling to a defined area requires the installation of many individual spraying devices which increases the cost of such in-the-ground systems.
Many attempts have been made in the past to provide some sort of apparatus which could alter the dispersal of water from a circular arc perimeter pattern and to also maintain a uniform watering density by controlling the water discharge rate. Several examples of these attempts are shown in the following U.S. Pat. Nos.
1,593,918 to Stanton; PA1 2,421,551 to Dunham; PA1 2,565,926 to Manning; PA1 2,582,158 to Porter; PA1 2,962,220 to Woods; PA1 2,999,645 to Kennedy; PA1 3,033,469 to Green; PA1 3,070,314 to Warren; PA1 3,070,315 to Landry; PA1 3,081,039 to Kennedy; PA1 3,082,958 to Thomas; PA1 3,204,874 to Senninger; PA1 3,606,163 to Lewis; and PA1 4,277,029 to Rabitsch.
However, none of these patents teach camming surfaces which are easily adjustable to provide for variation of the spray pattern for dispensing water onto or over any shaped area.
My copending U.S. patent application Ser. No. 557,734, filed on Dec. 2, 1983, solves this drawback, among others, of the heretofore known sprinklers.
A further problem with heretofore known sprinkler devices is that they rotate at a constant speed and dispense a constant volume rate of flow of water as they rotate. The result is that, of course, the further the zone to be watered is from the sprinkler device, the larger is the geometric area to which the water is to be applied. The result is that area to be watered furthest from the sprinkler device will receive a lesser amount of water per unit area than will smaller, closer-in areas.
Another problem with heretofore known sprinkler devices is that they do not provide for maintaining a desired or uniform watering density as the pattern of the area to be watered changes because the area changes as a function of the distance from the sprinkler device.
One attempt to overcome this drawback in rotary reaction type sprinkler devices is shown in U.S. Pat. No. 3,979,066 issued on Sept. 7, 1976 to Fortner. However, the device of Fortner can only be used on reaction type sprinkler devices. Further, in the device of Fortner the rotational speed of a reaction sprinkler to one and only one speed must be set the start of a sprinkling event, and can be not be used to provide continuous changing rotational speeds during each cycle of the sprinkler device. Even further, the device of Fortner is useable only on sprinkler devices which rotate in one direction, but is not capable of functioning on oscillatory sprinkler devices.
The present invention recognizes the drawbacks of the sprinkler devices heretofore known to me and provides a solution which is straightforward and easy to maintain in operation.